Hydraulic flow regulator



July 21, 1953 H. HOLLAND y HYDRAULIC FLOW REGULATQR Filed June 25, 1947 Y I l Herman Holland JNVENTOR.

Patented July 21,1953V l HermanH'ollani San Diego,` ('Jalif.,Y assignor to Consolidated- Vultee Aircraft Corporation, a

' corporation of Delaware v f .Application Jumi.l .125, 19427,'seiilirof'zszzz l A I The present invention relates to the regulation of fluid flow and more particularly to improved Yilovv regulator valves andsystems for the parallel operation of a pluralityv of fluid motors.

In fluid actuating systems wherein a'pluralit-yV individual loads on each of the actuating motorsg,

however, differ to any extent,V the most' heavily loaded'device usually lags behind those which are Claims'.` (CL-13745509) yio vmore lightly loaded. The present invention is f accordingly more particularly directed' to the provision of improved flow regulator valves and systems for maintaining the synchronized'operation of such multiple actuationv cylinders or motors.

' It is therefore a primary object'of thisinvention to providean improved regulator valve for Ya multiple motor system Whichwill regulate the flow of fluid to each motor in such manner'that they are each moved in unisonregardless ofi the )individual load imposed on the respective cyl# inders. A further object of the present invention resides inthe provision of a regulator valvevwhich is reasonably produced, is compact and foolproof in construction and operation., and which requires relatively little maintenance and servicing.A` `A still further objectr of the present invention' 'the provisioncof animprmfed hydraulic system utilizing a plurality of improved regulator valves' in conjunction with the parallel'operationoffa plurality of actuating cylinders for the synchronized movement of individually varying loads; AIt it a still further object to provide such an ,imJ

vrFig. lis avschematic diagram of an improved hydraulicJsystem embodying the flow regulator valves of .the .present invention; y

lig.A 2 is a'p'erspective cross-sectional view of the improved flow regulator valves shown in the system' in Fig. l; and Y y c Fig. 3 is across-sectional View of a modified form ofow regulator valve. Referring now to the system shown in Fig. 1, thenumeral indicates a reservoir for the storage ,of a liquid, oil Vorother suitable hydraulic uid to be lutilized in the actuating system. The reservoir 5 is` preferably provided with a Iiller connection and vent (notY shown) and with an outlet connection to the :suction side of the pump 6- driven-by the motor 1. Thepump `6 discharges the hydraulic iiuid' at a suitably high pressure into thepressure 'regulator valve 8 which preferably isjnset to maintain the desired operating pressure. The fluid, passing through the regulator valve 8, dischargesinto the main 'pressure line 9, and in the event thepressure delivered to this pressure regulator exceeds thev predetermined system pressure, a portion Vof the iluid is returnd through `the kry-pass connection I Vinto the return line I'3, through which it ilows back into the reservoir 5. l f

f ,'Ifhe'main 'pressure line Illows to the directional controler distributing valve I I which is so ported thatfit .can be manually operated to cause the v press'ure'-ow from' the lineS to be open to the pressure linell4, .whileat the same time providing proved hydraulic system utilizing the novel flow regulator valve of the present inventionjinwhich the valves may be 'set for a given working pressure to be used Within the` system and the actuating motors will operate in synchronismdespite a variation in the/loads which may be applied to them. `Still further objectives of the present invention reside in the improved construction of the valves per se as well as in their particular relationship tothe actuating cylinders and the other elements of the improved operating system.

Other objects and advantages of the present invention Will occur to those skilled inthe art after reading the present descriptionutaken tof ,a"fluidcommunication4 from the return line 23 to thegreturnlinedZ, which is opened to the aforementioned returnV Isto'the reservoir 5. j Alternatively,V the distributing valve ;II may beadjusiedto theposition in which the ports between th'ef lines `I,2,ar'.1d I4 are'in communication, and the pressure from the line 9 isv caused to ow into the, line 23, for the reverse operation of the system, I'n the positionin which the valve II is set in-Fig. l the-,portsfor'the conduits9 and I4 are in .communication for pressure ow into the line I4; and-the ports for the conduits I2 and 23 are incommunication for return flow yto the reservoir 5 y The pressure line I4 is provided with a branch communication for the initial flow regulator valve nI5, and-theY continuation of the pressure line I4 communicates with a second and like ow regulator valvel I6. The fluid outlet of the rst ow regulator valve vI5 communicates through the 'conduit' II with VtheV lower end of the actuating cylinder I9, and similarly the outlet of the second valve I6 communicates by means of the conduit I8 with the actuating cylinder or motor 20. It will be understood that the uid actuating cylinders I9 and 2U are of the type in which a piston is iixed at the lower end of the respective piston rods 24 and 25 and that the respective cylinders are provided with fluid connections 2| and 22 on cylinders, such as I9 and 20, opposed in Itheir Y movements by different loads such as 26 and 21, the least loaded cylinder I9 would travel the extent of its stroke at a much higher rate of speed" than the more heavily loaded cylinder 20. Such differential in the ratesof travel between the Apistons within the cylinders I9 vand v20 is caused by .the back pressure created -by the lighter load 26 which is appreciably less than the back .pressure created by the heavier load '2.1. This irregularity in the movement of the respective loads, er the differential in piston travel. is corrected by the inclusion in the respective pressure branches of the improved regulator control valves I and` I6.

These volume or flow regulator control valves I5 and I5, which are described below ,in detail in conjunction with the description of Figs. 2 `and 3, consist essentially of a variable orifice restrictcr needle valve .in which the orice area in a diaphragm vis controlled by a tapered pin of the needle valve. The loads on the respective hydraulic pistons .create back pressures which act upon these needle valves causing them to become displaced so that the crice areas become enlarged, thereby regulating the volume or flow on the theory that'the flow through an orice in lcubic inches, or other volume per minute, depends primarily upon the area of the orice and the difference in pressure on the opposite sides of the orifice. Accordingly, by means ofthe flow regulator valves I5 and I6, when the distributing valve is operated such that the pressure within the conduit 9 flows into the rline I4, the pistons within the respective cylinders I9 and 20 .move outwardly or upwardly at precisely the same rate, despite the fact that one is 'loaded several times more than the other.v For the purposes of explanation and simplification, the system in'Fig. l is intended to move the loads upwardly `only at the same rate rof speed, and in the event itis desired that the pistons also operate in the reverse direction simultaneously, it will be necessary to add similar flow control valves 28 and 29 where indicated by the dotted lines in the conduits 2| and 22,'respectively.

A preferred form of the flow regulating valves I5 and I6, of the system shown in Fig. 1 is shown in detail in the cross section in Fig. 2. This valve has a main body or cylindrical portion 30 into one end of which a further cylindrical body portion 3i of somewhat lesser diameter is threadedly engaged at 32. The opposite end of t-he main body 36 is internally threaded to provide anl outlet port or connection 33 and a cylindrical chamber portion 36a is formed between the threaded ends 32 and 33. The main body 30 is also provided with a laterally or upwardly facing threaded inlet 34 and an inlet aperture 35 engageable respectively by the needle valve fitting 36 and the needle valve 31. The outer terminal of the tting 36 is internally threaded at 38 to provide an inlet connection and the adjacent chamber has transversely fitted therein an oriced diaphragm 39 within which the needle portion 46 of the valve 31 is adapted to move in an axial direction. The main cylindrical portion of the needle valve 31 is provided with a longitudinal port or `passage 4I and the inner end of the valve Ais conically formed as at A42.

Within the chamber portion 33a of the main V`valve body 39 there is provided a conic cam element 43 aixed to one terminal of a piston rod 44, to the other end of which there is fixed the piston 45 provided with a hydraulic seal 46. The

-conicA cam 43is provided with peripheral ports 41 which permit uid pressure to flow past the `conic cam ,43 into either end of the chamber 30a, whereby this uid pressure may be exerted upon the piston 45 which is reciprocally mounted for axial movement within'the cylindrical bore Ellar of the cylindrical housing 3l. Outward movement of the .piston 45 under this pressure is opposed by a compression spring 43 disposed within the cylinder 3Ia,.the outer end of which is .closed by a plug 49 which alsoserves as an ad. justment means for varying the compression of the .spring 48 to the predetermined resistance which it `is desired be opposed to the fluid pressure within the main chamber 36a. lThe cylinder 3I is provided with a suitable bleed or relief Aaperture 3Ib to permit relief of pressures which may be developed within the cylinder 3Ia by movement of the piston 45 therein. A suitable .detent or stop (not shown) is preferably interposed in the path of the piston 45 to prevent its inadvertent emergence from within the Abore 3Ia. v The operation of the valve i3 shown in Fig. 2 is as follows:

The fluid under pressure enters the inlet port 38 passing through the `orifice between the diaphragm 39 and the conic needle valve portion 46, thence through the port or passageway 4I in the cylindrical valve portion 31 and into the main valve chamber 36a, from whence it is permitted to pass outwardly through the valve outlet 33 -to the hydraulic cylinder or motor I9, or other actuating means. In the actuation of the cylinder I9, or other power means, a back pressure is developed by the load opposed to the working cylinder. This back pressure is distributed through the ports 4l' in the conic cam 43 .in such manner that the back pressure becomes equalized at both ends of the main chamber 39a. Such back Vpressure is accordingly exerted upon the end face of the piston '35 causing it to be displaced outwardly against the resistance of the compression spring 48 and due to the interconnection of the piston 45 with the cam 43, through the intermediacy of the connecting piston rod 44, the conic cam 43 moves outwardly to a similar extent. inasmuch as the conic end 42 of the needle valve 31 is maintained in contact with the conic cam face 43 as the result of the inward now from the pressure line connected at 38 into the chamber 33a, the needle valve 31 will be caused to move inwardly into the chamber 30a as the cam 43 is moved away from the'outlet 33 by this back pressure. As the needle valve 31 is acted upon by the differential in the pressures at the orifice in the diaphragm 39 its displacement, in order to accommodate the new position of the conical cam 43, will cause an increase in the area of the annular opening within the aperture 39 and about the pin portion 43 of the needle valve 31. This increase in area ward movement ofthe piston 45, the airv entrained within the cylinder 3Ia is displaced-to the atmosphere through the opening 3Ib and the rubber doughnut seal 4B serves to prevent hydraulic uid within thesystem from passing into the chamber 3 I a past the piston 55, j

The modied form of the iiow regulatorvalve shown in Fig. 3 comprises a main body or block 50 having a threaded inlet connection 5I adapted to receive the similarly threaded inlet fitting 52 which lalso is provided with the metering `or nozzle orifice 55 at its inner end. A needle valve 54 is reciprocally mounted within the body 50 in axial alignment with the orice 53 and has a reduced diameter metering end portion 55 coaxially disposed within the nozzle orifice 53. The opposite end of the needle valve 5d is provided with a ball contact 5t and an intermediate portion is provided with a pressure seal 5l' to prevent hydraulic fluid from passing through the body portion within which the needle valve is movable.

Within the valve body 5e there is a needle valve chamber 58 surrounding the valve 54 and providing direct communication from the inlet 52` of the body 50, past the nozzle orifice 53, and direct communication with the threaded outlet 59. Within the body portion opposite the outlet 59, and in communication with the valve chamber 58, is a cylindrical passage or duct 5 communicating with a transverse duct 6 I, being closed by the threaded plugs 62 and 63, respectively. Parallel to the passage 5S and'on the opposite side of the valve body 50 there is a cylindrical bore 64 axially aligned with a larger cylindrical bore 65. An adjustably threaded plug 6'5 closes the far end of the enlarged cylindrical bore 55 within which the conic cam El is adapted to be slidably guided by the guide piston portions 68 and 69,.

To the opposite side of the piston 59 there extendsv a connecting or piston rod lil at the end of which is xed a piston 'iI of relatively smaller diameter than the guide pistons 68 and 65, to

slidablyv t within the cylindrical bore 54. The piston 'II carries Va hydraulic'seal, preferably of the ring type at 'l2 to prevent iiuid under pressure within the passages 60 and 6I exerted against the end of the piston 'II from passing into the bore beyond the piston toward the guide piston SS. Small amounts of hydraulic fluid, however, which may leak past the seal 'i2 are permitted to drain out through the drain passage 58a which also permits entrapped air displaced by the guide piston 59 to pass to the atmosphere and thereby The operation ofthe modified form of the valve shown in Fig. 3 is substantially the same as that ofvalves I5 and I6, shownin Figs. 1 and2. The most essential difference in the'operation rof vthe two valves lies inthat the conic cam portion 67 of the valve of Fig. 3 operates within an air cylinder rather-than directly inthe hydraulic fluid stream as in the case of the conic cam 43. This is accomplished in the Fig. 3 modication by providing the additional fluid passages 60, 6I and 84, causing the small plunger piston II to be exposed to the system pressure. Another difference in the operation of these two valves resides in the provision of the straight cylindrical lportion of the needle valve terminating in the conic metering portions 55a and 55h, which causes a uniform metering over an extended portion of the movement of the conic cam and of the like movement of the needle valve 54 while the cylindrical portion 55 is disposed within the orifice 53; with an increasing rate of now as the conic end 55a is disposed within the orifice; and a decreased rate of iiow as the larger conic portion 55h nears the same orifice. Theoperation of the modification of the valve` of Fig. 3 is accordingly as follows: 1

Y With the `metering pin portion 55 disposed with-` in the orifice 53 as shown in the gure, the rate of flow from the inlet 52 vto the outlet 59 is of an intermediate magnitude, and as' the load upon the hydraulic motor connected to the outlet 59 is increased and back pressure is created, it is reflected through the passages 5I) and 6I into the end of the bore 64 and against the end of the piston 'I I. This causes outward movement of the piston 'IVI and the attached conic cam 61, guided by the pistons 68 and 69, permitting the ball follower 56 on the needle valve 54 to move downwardly toward the axis of the conic cam 61. Should the back pressureso developed become sufficiently great, the outward movement ofthe piston 'Il and itsattached components compressing the spring 'I3 beyond a predetermined extent, the needle valve 54 is permitted to move further downwardly as the conic cam 61 moves outwardly permitting the conic end portion 55a to pass downwardly across the restricted portion of the orificev 53. As the cross-sectional area of the resulting opening increases, however, increased flow passes through the orice and the more heavily loaded oppositionv to thehydraulic motorcausing the back pressure is overcome by the additional fluid now which maintains the desired rate of relieve any pressures which might be developed between the pistons 55 and ll.

The opposite side of the guide piston 58 is provided with an extended stubV portion 68a which serves to guide and retain the end of a compression spring 'I3 which abuts at its opposite end against the above-mentioned end plug 66 threadedly engaging the main body 50 at the threads '14. 4The end plug 65 is also provided with a relief opening a through which` any entrained air within the adjacent portion of the cylinder 65 may be discharged to the atmosphere upon outward movement of the conic cam 6l against the compression spring 13.

movement of the moving parts of the hydraulic motor andits accompanying load. Similarly as the back pressure may again fall off, the spring *i3 causes the conic'piston to move inwardly again as the pressure in the bore 5s against the end of the piston 'II is reduced and the straight cylindrical portion of the metering pin 55 .again becomes disposed within the orifice 53. As mentioned above, the air within the. outer portion of the cylinder 65 is displaced upon outward movement of the conic cam Sl. through the orifice 66a and as the conic cam' 6l returns'in its inward movement, the air is permitted to return, andthe air ahead of the guide piston Gil is then permitted to be relieved through the vent passage 55a. d

In the system shown in Fig. l in whichfthe pistons 2d and 25'are synchronized in their upward strokes only, it will be obvious that the return` of the pistonsv to their retracted positions is accomplished by adjustment of the distributing valve II to feed the hydraulic pressure fluids from the conduit 9 into the conduits 23, 2| and 22 to the upper ends of the Vcylinders and returning the same under unequal rates of travel in view of their unequal loading, or in the event they become unloaded at the end of their upstroke, they would be returned at equal rates of travel. In such a situation, the hydraulic flow regulator in the lower part of the system acts merely as by-pass valves and the fluid which is forced from the lower part of the cylinder acts to release the metering pin by forcing over the cam on which it is sustained to permit the fluid to be returned to the reservoir or accumulator, and is merely a reversal of the original action of the valve. rIhe adjusting nuts de and 66 which are incorporated in the respective modifications of the valve, are utilized toadjust the spring characteristics for speciiic applications in which the valves are used and it is not necessary that these nuts be adjusted once the spring has been set. For example, should it be desired to use the valves in a 3000 p. s. i. hydraulic system, the spring will be adjusted by the taking up of the nuts to the required spring resistance and once having been so adjusted, no further calibration will be necessary. Thus, identically adjusted regulator valves will cause differently loaded cylinders to be operated in unison. The valves shown have been tested with loads varying from 150 to 800 pounds diierence and it was found that the two cylinders subjected to the different loads moved uniformally when the hydraulic flow at each cylinder was regulated by the piesent valve.

As has been indicated above, in connection with the description of Fig. l, when only two of the hydraulic flow regulator Valves,.such as l and I6, are incorporated in the system, the return movement of the pistons would not be in unison. However, in applications where unequal loads would be borne both on the outward and inward strokes, it may be desirable to provide a modification of the system shown in Fig. i in which an additional pair of flow regulator valves 281V and 29 would be provided in order to equalize the return rates of movement also. Similar results, however, may be obtained by the use of a dual type distributing valve in conjunction with but one flow regulator control valve`for each actuating cylinder. In the latter system, this would be accomplished by a dual, or a pair of i simultaneously actuated, distributing valves installed on the actuating cylinder side of the flow regulator valves and ported such that the flow of the pressure fluid would always be through the regulator valves in the same direction.

The present hydraulic actuating system and the improved regulator valves have proven a particularly efficient means for regulating the rates of travel of hydraulic cylinders in a parallel system such as the hydraulic landing gears of aircraft, as well as the wing ilaps and cowl jacks used on airplanes. The present invention is not, however, limited to the actuation of these or tended to come within the scope and spirit of this invention as more particularly set forth in the following claims.

I claim:

. l. A flow regulatorvalve comprising a valve body having inlet and outlet connections, a iiuid passage extending between said inlet and outlet connections, a cylindrical bore within said valve body having one end of saidbore in communication with said iiuid passage, a spring-opposed conic camming piston axially movable within said cylindrical bore in response to iiuid pressures developed in the region of said outlet connection and transmitted through said iiuid passage to said open end of said cylindrical bore, non-closable metering valve means including an axially floating element operatively disposed within said Yduid passage on the inlet connection side of said iiuid passage, said valve means having an opposite terminal in sliding contact with `said camming piston, said valve means movable in response to movement of said camming piston whereby increased pressure in the region of said outlet connection initiates movement of said camming piston and further opening of said metering valve means for the increased iiow 'through said iiuid passage, said camming piston and said metering valve means each provided with fluid seals against said valve body whereby said camming piston does not work within the same system fluid being regulated by said valve.

2. A flow regulator valve comprising a valve body provided with an inlet connection and an outlet connection, a iuid passage extending between said inlet and outlet comiections, a main bore portion within said valve body, a supplemental bore portion having one end open to and in axial alignment with said main bore portion, the opposite end of said supplemental bore portion being open to said fluid passage, a spring opposed conic piston assembly having piston portions axially movable within each of said bore portions in response to pressure at said outlet connection, an axially movable needle valve element reciprocable within a further bore portion in said valve body between said inlet connection and said main bore portion, said needle valve element having a pointed terminal portion directed toward said inlet connection and an opposite contact portion in engagement with a conic piston of said piston assembly in such manner that said needle valve element is movable in response to axial movement of said conic piston assembly, said needle valve element having its pointed terminal portion directed into the iiuid flow into said inlet connection in such manner that said needle valve element is urged into Contact with said conic piston, and an orifice disposed within said iiud passage adjacent said inlet connection arranged to be regulated by said needle valve element for increased flow as pressure within said outlet connection is increased thereby initiating movement of said conic pistonportion and said needle valve element, said conic piston assembly and said needle valve element each provided with fluidtight seals against said respective bores whereby said piston assembly is not required to operate within the same system fluid being regulated by the flow regulator valve.

.3. In a flow regulator valve the combination Wlth fl body portion having inlet and outlet ports therein, a cylindrical bore within said bodvportion in communication with said inlet and outlet ports, a piston having a conic cam axially movable within said cylindrical bore portion under the influence of back pressure within said outlet port and adjustable spring means for opposing the axial movement of said camming piston, of an orifice in communication with said inlet port and an axially iioating needle valve element having axially spaced conic portions and an intermediate metering portion extendable through said orifice and a further follower portion in contact with the conic cam of said piston whereby increased pressure movement of said piston imparts opening movement to said iloating needle Valve element and increased flow through said orifice, said needle valve element having a straight cylindrical portion between its conic portions for the uniform metering of the fluid over an extended portion between its opening and closing positions.

4. A hydraulic flow regulator valve comprising a body portion having inlet and outlet connections, a cylindrical bore portion within said valve body, a spring-opposed camming piston axially movable within said cylindrical bore portion, an axially iioating metering element disposed in a fluid passage extending between said inlet and outlet connections, said floating metering element having axially spaced Conic portions adjacent a first terminal of said element, said floating metering element having an opposite terminal portion in contact with said camming piston for axial movements upon movement of said camming piston resulting from increased pressures developed within said cylindrical bore portion, said floating metering element having a straight cylindrical portion disposed between said conic portions for uniform iluid metering over an extended movement, an orice disposed Wiithin said fluid passage for cooperating with said floating metering element whereby increased pressure within said cylindrical bore portions initiates movements of both camming piston and said floating metering element for increased flow through said fluid passage.

5. A flow regulator valve comprising a body portion, inlet and outlet ports within said body portion, a passage Within said body portion in communication with said inletl and outlet ports and providing for iluid flow therebetween, a cylindrical bore Within said body portion, a cam member adapted for axial movement within said cylindrical bore, a supplemental bore Within said body portion in axial alignment with and open to initiating axial said first cylindrical bore portion, said supplemental bore being in fluid communication with said liuid passage between said inlet and outlet ports, said cam member having an `attached piston portion axially movable within said supplemental bore, adjustable resilient means opposing axial movements of said cam member Within said cylindrical bore initiated by pressure actuated movements of said piston within said supplemental bore, an orifice disposed within said valve body across said uid inlet port, an axially floating needle valve member having axially spaced conic portions forming a metering end portion axially movable through said orii'icey said valve member having a straight cylindrical intermediate portion for uniform metering over an extended movement, said needle valve having a follower portion held in contact with said cam member by the fluid iow past said floating valve member in such manner that pres- HERMAN HOLLAND.

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